Doubts concerning the inversion of objects on the retina / by Marmaduke Berdoe.

  • Marmaduke Berdoe
Date:
1772
Catalogue details

Licence: Public Domain Mark

Credit: Doubts concerning the inversion of objects on the retina / by Marmaduke Berdoe. Source: Wellcome Collection.

    46/98 (page 40)
    [ 4° ] C D, as in 1,2,3,455, mark'd on that membrane. From this circum(lance it mull t, manifedly follow, that the eye receives two oppofed and different impulfions, excepting thofe which are made in the central points, 3 M L, 3 I K. Were it really the cafe, that the paintings of every objet mud abfolutely be delineated on the retina to caufe perfet vifion, and that fuch delineation was al¬ ways inverted, in fuch cafe 1 am alrnoft perfuaded in my own judgment, that the eye mud befenfible of the two different iru¬ pee dions made on it, and mud be fol¬ lowed by a confufion in the faculties of this fenfe. For the extreme fenhbility of the external membrane, or the conjunctive, mud render its affetions of material con- fequence to the fenfations. But in fat, ■ r *, ■ 1 vifion in the human body is both perfet and imperfet. The manner in which I make this didintion is, by calling imperfet vifion all that circle of perceptions beheld by the tranfparent cornea ; and perfet vifion that cone of rays which dimulates the retina^